As the global burden of diabetes continues to rise, health professionals in South Africa and around the world are working to raise awareness not only about the well-known Type 1 and Type 2 diabetes, but also lesser-known variants. One such variant is now gaining the attention it deserves: Type 5 diabetes, also known as Malnutrition-Related Diabetes Mellitus (MRDM).
This recently reclassified form of it is not new in medical history, but its formal global recognition has sparked new discussions around nutrition, poverty, and misdiagnosis, especially in developing countries such as South Africa.
It is currently estimated that one in nine South Africans lives with some form of diabetes mellitus. With such high prevalence, national health authorities and healthcare practitioners continue to campaign for increased testing, earlier diagnosis, and improved treatment plans.
“People are mostly familiar with Type 1, where the pancreas produces little to no insulin, and Type 2, where the body resists insulin or doesn’t use it effectively,” explains Dr Fundile Nyati, CEO of Proactive Health Solutions.
“However, we now acknowledge a broader spectrum of the disease. There’s gestational diabetes, which occurs during pregnancy, and Type 3, linked to direct pancreatic disease. Type 4, though still under investigation, has been associated with conditions like glaucoma and sometimes referred to as ‘brain-associated diabetes mellitus.’ And now, we have Type 5 — a distinct and critical classification.”
Type 5 Diabetes: A Silent Threat in Undernourished Communities
Type 5 diabetes was formally recognised in January 2025 during an international summit of diabetes experts in India. It was later endorsed by the International Diabetes Federation at its World Congress in Thailand in April 2025.
But this form of diabetes was first described as far back as 1955, by a physician in Jamaica. It took 30 years for the World Health Organization (WHO) to formally recognise the condition in 1985 under the name malnutrition-related diabetes mellitus. Unfortunately, this classification was dropped in 1999 due to limited supporting research — a decision that some experts, including Dr Nyati, believe contributed to decades of misdiagnosis.
“Now that it’s back on the table as Type 5, we have a real opportunity to improve diagnosis and outcomes,” says Dr Nyati. “Especially in countries like South Africa, where poverty and undernutrition remain major public health challenges.”
Type 5 is directly linked to chronic undernutrition, particularly during in utero development and early childhood. Malnutrition during these key developmental periods can lead to abnormal pancreatic development, impairing the organ’s ability to produce insulin effectively later in life.
People living with Type 5 often present with distinct characteristics:
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A history of malnutrition from birth or early childhood
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Underweight body mass index (BMI below 18.5)
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Severe impairment in insulin production
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Absence of insulin-resistance indicators or autoimmune markers found in other types of diabetes
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High blood sugar levels in adolescence or early adulthood
Unlike Type 2 dibetes, where the body resists insulin, individuals with Type 5 often have fully functional insulin receptors. However, due to a weakened or underdeveloped pancreas, they struggle to produce enough insulin naturally.
Due to overlapping symptoms, individuals with Type 5 diabetes are frequently misdiagnosed as having Type 1 diabetes. This is where the risks become severe.
“Many of these patients are put on full insulin therapy, which can lead to serious complications,” warns Dr Nyati. “They actually respond far better to oral medications typically used for Type 2, with only small supplemental insulin doses needed.”
This makes proper diagnosis — and awareness of Type 5 — essential. The wrong treatment can not only worsen their condition but, in extreme cases, lead to death.
South Africa, as a low- to middle-income country, is especially vulnerable to the effects of undernutrition, particularly in rural areas. The growing recognition of Type 5 diabetes presents an opportunity to address a major gap in health care — by identifying those who may have gone undiagnosed or misdiagnosed for years.
“Type 5 is especially relevant here,” says Dr Nyati. “We need more local research, more clinician awareness, and better health screening in under-resourced communities.”
The reclassification of malnutrition-related diabetes as Type 5 is more than a medical footnote — it’s a public health call to action. Health systems must adapt their diagnostic frameworks, train medical professionals to recognise the signs, and begin tracking Type 5 as a unique health condition requiring tailored treatment strategies.
Most importantly, it reminds us of the deep connection between nutrition, socio-economic status, and chronic disease — especially in vulnerable communities.
As the definition of diabetes evolves, so too must our understanding, outreach, and response. With proper education and policy changes, we can ensure that Type 5 is no longer the hidden variant in South Africa’s fight against a growing epidemic.
Source- EWN
